Last Updated: May 17, 2021

Avocados are premium fruits, and that’s why brown spots in them can be disheartening. But most of the time, theses spots aren’t the work of you and i but of individuals bossing it along the farm to table supply chain, and often at times, of the fruit itself.

In this article, we discuss some of the reasons why brown spots can develop inside avocados and what you can do with the affected fruits.

1) Brown spots in avocados may be due to vascular browning

Vascular browning is a situation where the vascular bundles that run through the avocado flesh trade their quite coloration for a brown one and thus become more prominent.

These vascular bundles, or veins as i prefer to call them, are the brown strings you see whenever when you cut some avocados, and the good thing about them is that they are perfectly okay to consume without any health implications, except that they might bear some icky kind of texture.

Vascular browning in avocados may or may not be visible upon cutting the fruit in half, you may need to scoop out the flesh or begin mashing with a fork to observe the strings in some cases.

Vascular browning in avocados typically isn’t something that you can prevent at home because the issue is primarily caused by pathogens during growth as stated by the Avocado Fruit Quality Problem Solver (which is an avocado guide published by the Applied Horticultural Research).

Additionally, they may easily be aggravated by practices and methods employed during their transit from farm to table.

At home however, you can aggravate the problem with long storage and freezing of the fruits.

Here is a look on some of the factors that contribute to more vascular browning in avocados.

—Your avocado is of the variety that is prone to streaking inside

As continuation of the above point, if you have a variety of avocado prone to streaking inside like the rich, nutty-flavored variety; stuart, then you’ll be dealing with more of these lines in your fruits when vascular browning decides to kicks in.

—Your avocado is an early season harvest

With respect to vascular browning and the season here in the United States, early season avocados tend to be affected more by it than mid or late season fruit. So if you could, delay your avocado cravings until mid or late season to enjoy higher chances of fruits that are free of string.

—Your avocado was harvested immature

According to many sources, immature avocados are more prone to developing streaks in them than their mature counterparts. So if you have an avocado fruit with strings, one of the possible reasons could be that you have an avocado that was plucked even before it attained the minimum level of maturity.

2) Its enzymatic browning

One chief cause of browning in many fruits, not just with avocados is enzymatic browning, which is the reaction that occurs naturally within aged fruits that cause them to adopt a brown coloration, but it’s also accelerated within fruits that have picked up bruises or have been cut in pieces.

Enzymatic browning requires oxygen to take place and it is usually triggered when the cells and structure of a fruit breakdown naturally or with applied force giving way for oxygen to kick start the reaction.

For aged fruits, their cells naturally breakdown as they age thus allowing spaces for oxygen to enter into them and cause the reaction to happen.

In whole bruised fruits, there is browning on both the inside and outside due to the formation of cracks which forms air cavity between the flesh and skin, thus supplying oxygen for the reaction to take place.

As for cut fruit, how they brown is pretty obvious, their exposed flesh is in direct contact with oxygen which cause the reaction to occur.

When you have a whole avocado with brown spots inside, your case might be nothing short of the “bruised whole fruit” problem, and the bruise might have been caused by you while checking the fruit for ripeness, or at the retails’, the supermarket or elsewhere along the farm to table chain. You may not necessarily see the bruising on the green sturdy fruit, but as it ages, the bruised or pressured part breaks down faster than the rest, and thus goes brown faster too.

That’s why it’s always advised to test fruits for ripeness by placing them inside your palm and squeezing gently for the ‘give’ rather than poking with a finger.

3) You avocado is rotten

It’s no brainer, if it’s neither any of the items on the list, then it’s definitely a rotten avocado. These develop brown and black spots on the inside and outside and these spots often form a hardened point that runs from outside to insides in the affected spots.

Rotten avocados can be caused by a variety of avocado pests and mold, and they are generally advised to be discarded rather than consumed by removing and discarding the affected parts, especially when it’s a mold colonizing the fruit.

4) You have an overripe avocado

When you have an overripe avocado fruit, it’s only natural for it to begin to turn brown due to enzymatic browning. And when it extends past ripeness, it rots, which therefore means that it’s getting colonized by a variety of pests that would naturally cause it to rot.

When your avocado smells funny and textures funny too, discard it and try your luck with another.

5) You avocado is suffering from chilling injury

Another cause for browned avocado is chilling injury which is inflicted upon fruits by long storage at low temperatures. Got it? Frozen avocados!

If you froze your avocados for long, then it shouldn’t be surprising that they developed spots on the flesh. There a variety of factors that can also contribute to this aside the long storage time and temperature being the main culprits.

Frequently Asked Question

How do you know when an avocado goes bad?

An avocado is bad when it feels extremely soft to the touch and would often have a dented outer skin. When cut, the inside of a rotten avocado is most likely brown, with a smell and flavor distinct from that of a regular avocado.

While true that it’s mostly overripe avocados that go bad, green fruits too can become rotten on the inside due to a variety of factors. For them, there could be spots all over the surface of the avocado and the inside would most likely have many hardened spots or mold growth.

What happens when you eat a rancid avocado?

While most people would most likely get away with eating a rancid avocado, those compromised can actually get sick from it. Because there isn’t any tag on your forehead to indicate how healthy you are from the inside, it’s better to err on the side of caution and avoid eating rancid avocados. Do you even know what it means? An avocado that is most likely rotten!

Is overripe avocado dangerous?

No, eating overripe avocado is perfectly fine so long the fruit isn’t moldy on the inside or taste off flavored. Overripe avocados are perfect for mushing up, although their taste wouldn’t be as sharp as that of a perfectly ripe avocado fruit.

Can you eat brown avocado?

Brown avocados are safe to eat so long they don’t smell funny and texture slimy. This means that you can eat avocados with strings in them or those with brown spots caused by one or two reasons.

Dark rooty lines in avocado

The dark rooty lines in avocado is due to a phenomenon called vascular browning, which cause the vascular bundles running throughout the avocado flesh to adopt a brown coloration. Vascular browning may be caused by pathogens and can be aggravated by season, level of maturity of fruit prior to plucking, variety if fruit and also chilling.

While unappealing, avocados having dark rooty lines are perfectly safe to consume without any health effects, so long they don’t smell texture funny.

Final Verdict

There are many reasons as to why an avocado flesh can develop brown spot. Some spots can be cause by vascular browning which is the browning of the vascular bundles that run through the avocado flesh and supplies it with nutrients, while other can be cause by mold growth, pests, chilling, or an overripe fruit.

Depending on the cause, avocados with brown spots may be edible. For example, avocados impacted with vascular browning are mostly edible whereas those having mold growth in them are better discarded. Whatever, just make sure you use the acid test of sight and smell to decide which avocado goes into your stomach and which doesn’t.

And I hope these organs are in the best possible state they could ever be!